An increase in the activity of matrix metalloproteinase-9 (MMP-9) relative to tissue inhibitor of MMP-type 1 (TIMP-1) may be related to formation of new MS lesions, suggesting that serum levels of MMP-9 and TIMP-1 may be surrogate markers of disease activity in relapsing-remitting MS.

Quantitative MRI measures are diffusely abnormal in MS NAWM. These measures are, on average, more abnormal in NAWM regions in which new Gd+ lesions arise. After the appearance of Gd+ lesions, measures of PDN and MTR may provide more appealing markers of relatively irreversible tissue damage than measures of T2 and T1N.

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The structural integrity of wind turbine blades can be adversely affected by their structural dynamics, temperature extremes, lightning strikes, ultraviolet radiation from sunlight and airborne particulate matter such as hailstones and sand. If subsurface delamination occurs and is undetected then this can lead to fibre breakage and catastrophic failures in composite blades. In this paper we introduce a microwave scanning technique that detects such delamination in practical blade assemblies. Using an open-ended waveguide sensor, the electromagnetic signal reflected from the composite is found to have a phase profile that can detect changes in the composite cross section. Glass fibre T-joints are scanned and the results used to detect thickness variations (e.g., the presence of the web) and delamination. Results are compared across the 18-20 GHz frequency band. The dielectric permittivity of the composite system is measured and is used to estimate the stand-off distance and operating frequency of the sensor. This is critical to the system's ability to detect damage. When the sensor is close to the surface of the structure (standoff distance ≈ 5 mm), delamination down to 0.2 mm in width could be detected.

Based on the application requirements of the suspended microstrip circuit, a novel broadband microstrip line-suspended microstrip line transition circuit is designed in this paper. The transition structure uses "V-grooved" ground structure to realize the transition from microstrip line to suspended microstrip line in the direction of electric field, and uses gradient signal line for impedance matching to expand the bandwidth. The final simulation results show that the echo loss of the structure is better than 15 dB and the insertion loss is less than 0.165 dB in the frequency range of 0-40 GHz, and the sensitivity of circuit performance to circuit size is low. This design combines the ultra-low loss suspension line with the most commonly used microstrip line circuit, and has the advantages of broadband, low insertion loss, easy processing and compact structure. It improves the application scope of the suspension microstrip circuit and can be better integrated with other circuits or systems.

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The paper presents a quantitative damage evaluation of carbon-fibre reinforced polymer (CFRP) plates using a non-contact electromagnetic (EM) sensor. The EM sensor with coupled spiral inductors (CSI) is employed here to detect both impact induced and simulated damage leading to an accurate evaluation of the location, depth and width of sub-surface defects. The effect of inspection frequency, standoff distance and signal power are also investigated leading to the development of an engineering circuit design tool that relates the set up and calibration of the sensor to its detection performance. It is found that the dynamic range of the transmission coefficient is the limiting factor in the original Salski CSI sensor and this problem is addressed by adding ferrite layers to reduce the reluctance of the magnetic circuit, improving damage sensing by 22%. The study leads to a further development of utilising an open ferrite yoke with a pair of encircling coils, which shows a 57 % sensitivity improvement and clearer identification of air gaps (voids) and delamination in CFRP laminates. The proposed EM yoke design CSI sensor is low cost and could be assembled into an array for non-contact, in situ mechatronic scanning of aircraft composite wings.